The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A variety of computing devices support geographic software for displaying interactive digital maps of geographic areas. The geographic software typically provides directional, rotational, and zoom controls for positioning a window defining a viewable portion of the digital map, which can be referred as to as “viewport,” over the desired location. For example, these controls can be provided in the form of buttons overlaying the digital map. As another example, geographic software operating in a device equipped with a touchscreen can support user gestures, so that the user can pan across the digital map by swiping her finger in the desired direction, zoom in on an area by pinching two fingers together, zoom out on an area by spreading two fingers apart, etc.